This invention relates to sampling of fluid within a closed system, and more particularly, to a fitting of the type which allows sampling of said fluid, meanwhile maintaining the system in its closed condition.
The testing or trouble shooting of a mechanical apparatus such as power plant or engine often involves sampling the temperature and/or pressure of fluids within a closed system of the apparatus. These fluids may take the form of cooling, lubricating, or fuel agents, and variations in their temperature and/or pressure can indicate if the apparatus is functioning properly.
In order to sample a closed system fluid, it is the general practice to attach a fitting or valve of some type to a portion of the system carrying the fluid. Since the fluid will, of necessity, be exposed to the atmosphere for some limited period of time during connection of the fitting, the system or apparatus must be shut down to prevent loss of fluid and/or to prevent a safety hazard to personnel working on the system. Shutdown of the system or apparatus is time-consuming and often requires an additional running time to ring the fluid back to operating temperature or pressure after shutdown.
Additionally, connection of a fitting to the system generally results in some loss of fluid which must be replaced after the connection is completed.